为什么 RE ？？？

from math import *


changdu_list = ["mm","m","km"]
zhongliang_list = ["mg","g","kg"]
yuanlai = []
y_l_danwei = []
zhuanhuan = []
z_h_danwei = []
n = 0
def _input():
    global n
    n = int(input())
    for i in range(n):
        s = input().split(" ")
        yuanlai.append(int(s[0]))
        y_l_danwei.append(s[1])
        z_h_danwei.append(s[4])

def _print(i):
    print(yuanlai[i],y_l_danwei[i],"=",int(zhuanhuan[i]),z_h_danwei[i],sep=" ")

def jisuan():
    global n
    for i in range(n): # 遍历题目
        if y_l_danwei[i] in changdu_list:
            zhuanhuan.append(yuanlai[i]*pow(1000,changdu_list.index(y_l_danwei[i])-changdu_list.index(z_h_danwei[i])))
        else:
            zhuanhuan.append(yuanlai[i]*pow(1000,zhongliang_list.index(y_l_danwei[i])-zhongliang_list.index(z_h_danwei[i])))
        _print(i)

_input()
jisuan()

求助！感谢大佬